URL Encoder / Decoder — Free Online Tool

What Is URL Encoder / Decoder?

A free online URL encoder and decoder. Encode spaces, symbols, Unicode text, and query strings into valid URL-safe text, or decode encoded URLs back into readable form.

URL encoding, also known as percent-encoding, is the standard way to include special characters in URLs. Characters like spaces, symbols, and non-ASCII text must be encoded because URLs have a restricted set of allowed characters. URL Encoder/Decoder handles both encoding and decoding, making it easy to prepare URLs for API calls, redirects, and web development.

In Encode mode, the tool converts unsafe characters to their percent-encoded equivalents. A space becomes %20, an ampersand (&) becomes %26, an equals sign (=) becomes %3D, and Unicode characters like é become %C3%A9 (their UTF-8 byte representation). This ensures that query parameters, URL paths, and fragment identifiers are safely transmitted without being misinterpreted by browsers and servers.

In Decode mode, the reverse operation converts percent-encoded characters back to their human-readable form. This is essential for debugging API responses, reviewing tracking URLs, and understanding redirect chains. For example, a URL containing "q=hello%20world&category=%23web" decodes to "q=hello world&category=#web". The decoded form is what the server or browser actually interprets.

The bidirectional swap button lets you toggle between encode and decode instantly, which is useful for round-trip verification. The tool uses the standard JavaScript encodeURIComponent() and decodeURIComponent() functions, which handle all characters defined in the URI specification. Processing is entirely local with no server communication.

Real-World Use Cases for URL Encoder / Decoder

Encoding a Search Query String for an API Call

Your search API accepts a query parameter: "q=artificial intelligence & machine learning". The ampersand and spaces need encoding. Paste the query and encode: "q=artificial%20intelligence%20%26%20machine%20learning". The API now receives it as a single parameter value instead of splitting at &.

Decoding a Redirect URL to Understand Tracking Parameters

A marketing redirect URL contains "%7Bclick_id%7D" and "%26source%3Dnewsletter". Decode it to reveal "{click_id}" and "&source=newsletter". The decoded form helps you understand what tracking parameters the redirect is passing and what dynamic values are expected.

Preparing a URL that Contains Unicode Characters

A product page URL has a Japanese product name: "かわいい猫のぬいぐるみ". Encode the path to get "%E3%81%8B%E3%82%8F%E3%81%84%E3%81%84%E7%8C%AB%E3%81%AE%E3%81%AC%E3%81%84%E3%81%90%E3%82%8B%E3%81%BF". This percent-encoded version is what browsers send to servers for internationalized domain names and paths.

Why Use URL Encoder / Decoder?

Bidirectional URL encoding and decoding
Useful for query strings, redirects, and APIs
Handles spaces, symbols, and Unicode text
Runs locally with no network requests

How to Use URL Encoder / Decoder — Step by Step

Choose encode or decode mode.

Paste the URL or text you want to transform.

Review the converted result instantly.

Copy the output or swap it back into the other mode for quick debugging.

Who Is URL Encoder / Decoder Best For?

API debugging
redirect URLs
tracking parameters
web development

Pro Tips for URL Encoder / Decoder

1Use encodeURIComponent() for query parameter values (everything after ?). For the path portion of the URL, encodeURI() is more appropriate as it preserves / and ? characters.
2Always encode user-generated content before including it in URLs. Failure to encode can lead to parameter injection vulnerabilities where a user inserts & or = to manipulate query parameters.
3Modern browsers automatically encode spaces as %20 in URLs. Older systems may use + for spaces (application/x-www-form-urlencoded format). This tool uses %20, which is the standard URL encoding.
4When debugging double-encoding issues, decode multiple times. If the decoded output still contains %20 or %26, decode again until all encoded sequences are resolved.

URL Encoder / Decoder — Frequently Asked Questions

Why do URLs need encoding?

URLs can only safely contain certain characters. Spaces, symbols, and non-ASCII characters should be encoded so browsers and servers interpret the address correctly.

When should I decode a URL?

Decode a URL when you need to inspect query parameters, review redirects, debug API calls, or understand a link that contains encoded characters.

Can I use these tools with sensitive/proprietary data?

Absolutely. All processing runs locally in your browser with zero server uploads. This makes these tools safe for proprietary code, internal API keys, and confidential data.

Do these tools work offline?

Yes, once the page has loaded, most developer tools continue functioning without an internet connection. This makes them ideal for air-gapped environments or travel.

What browsers are supported?

All modern browsers are supported: Chrome, Firefox, Safari, and Edge. Internet Explorer is not supported. The tools leverage modern JavaScript APIs like Web Crypto, TextEncoder, and BigInt.

Ready to Use URL Encoder / Decoder?

Free online tool — works in your browser, no sign-up required. Start using it right now.

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